These triangles are used for calculations based on Ohms Law, where:

1

• These triangles are used for calculations based
  on Ohms Law, where
• W Watts a measure of power.
• I Intensity ( or amps - the amount of
  electricity flowing)
• V Volts The electrical pushing force.
• R Resistance, measured in ohms, symbol ?
• If we know any two of the variables in the
  triangles, we can calculate the third one.

2

• For example, suppose we have a problem, and we
  want to calculate how much current two 21Watt
  brake lamps consume in a vehicle fitted with a
  12Volt electrical system .
• In this case, we know the value for W, and the
  value for V, so if we use the triangle on the
  left, we can calculate how much current will be
  consumed.

3

• Substitute 42 as the value for W.

4

• Substitute 42 as the value for W.

• Substitute 12 as the value for V.

5

• Substitute 42 as the value for W.

• Substitute 12 as the value for V.

6

• Substitute 42 as the value for W.

• Substitute 12 as the value for V.

• The answer is calculated by dividing the 42 by
  12, giving us an answer of 3.5.
• This means that the two brake lamps consume 3.5
  amps of electricity.